An apparatus for making an adhesive tape having the above-described design is described in EP 1 108 769, for example. In that document, a substrate made of a nonwoven material is used that is provided with perforations. These perforations enable the adhesive tape manufactured in this manner to be torn in desired places. The perforations are made by thermal bonding.
Adhesive tapes and particularly wrapping tapes having the above-described construction are typically used to encase cable sets in automobiles. This is described in detail in DE 103 29 994, for example. A comparable approach constitutes subject matter of WO 2012/048912 [US 2013/0273333]. In both cases, the substrate is provided with one or more adhesive strips that cover only a fraction of the surface of the substrate.
The manufacture of adhesive tapes with strip-shaped adhesive coating is described in the applicant's application WO 2013/024150 [U.S. Pat. No. 9,222,002], for example. In that application, the process is typically such that the substrate strip made of the textile material is first unwound from the supply and then fed to the coater. With the aid of coater, one or more adhesive strips are produced on the substrate strip in its longitudinal extension by coating with an adhesive. Finally, the substrate strip is subdivided longitudinally into the individual adhesive tapes.
During the cutting operation, which can be performed with the aid of rotary cutters or also subsequently, so-called fraying can occur at the longitudinal edges or transverse edges and thus reach the cut edges. Such fraying or even yarn pull-out in ribbon-shaped textile substrates, which are made of nonwoven fabric or a woven fabric, for example, are sometimes only observed during use, that is during the wrapping of an elongated object. This can result in problems in the manufacture of a tubular sheath using the adhesive tape in question, or work is rendered utterly and excessively difficult.
It is true that the above-described prior art does typically work with rotary cutters that ensure a clean cut at the cut edges. What is more, the adhesive coating often ensures that the above-described fraying does not occur, at least not if the adhesive coating reaches to the longitudinal or transverse edge in question. However, since work is increasingly performed using strip-shaped adhesive coatings that do not cover the entire face of the substrate, the longitudinal edges are often free of the adhesive coating. As a result, the described fraying can occur at the longitudinal edges. Comparable fraying is sometimes also observed in perforations. To date, the prior art has not made any compelling solutions available in this regard.